Electrophotographic copy paper supply roll and mounting assembly therefor

ABSTRACT

A mounting assembly for an electrophotographic copy paper supply roll employed in an electrostatic copier includes a spindle removably mounted against rotation by a pair of end brackets secured to the copier frame. The core of the supply roll has a stepped bore and is mounted for rotation on a pair of different diameter hubs adjustably axially keyed on the spindle for varying supply roll widths. The assembly insures proper orientation of the photoconductive coating on the copy paper relative to the copier while maintaining the supply roll centrally positioned in relation to the optical axis thereof.

Waited States Schwartz atent 1 [54] ELECTROPHOTOGRAPHKC COPY PAPER SUPPLY ROLL AND MOUNTING ASSEMBLY THEREFOR [75] Inventor: HermanSchwartz,Wayne,NJ.

[73] Assignee: Pitney Bowes-Sage, lnc., Hawthorne,

45] May LBW/3 Primary ExaminerGeorge F. Mautz Assistant ExaminerEdward J. McCarthy Attorney-William D. Soltow, Jr., Albert W. Scribner, Martin D. Wittstein and Louis A. Tirelli [57] ABSTRACT A mounting assembly for an electrophotographic copy paper supply roll employed in an electrostatic copier includes a spindle removably mounted against rotation by a pair of end brackets secured to the copier frame. The core of the supply roll has a stepped bore and is mounted for rotation on a pair of different diameter hubs adjustably axially keyed on the spindle for varying supply roll widths. The assembly insures proper orientation of the photoconductive coating on the copy paper relative to the copier while maintaining the supply roll centrally positioned in relation to the optical axis thereof.

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INVENTOR HERMAN SCHWARTZ BY M a mm ATTORNEY ELECTROPI-IOTOGRAPHBC COPY PAPER SUPPLY ROLL AND MOUNTING ASSEMBLY THEREFOR BACKGROUND OF THE INVENTION some thought on the part of the operator. First of all,

the supply roll should be centrally positioned on its mounting assembly and the leading end portion of the copy paper web withdrawn from the supply roll to start the copy paper supply should be fairly accurately aligned with the supply roll. If these functions are not performed with reasonable care, the sheets cut from the copy paper web are skewed as they are conveyed along the copy paper feedpath through the copier. This materially increases the possibility of a paper jam, and

furthermore, the images reproduced on the copy sheets are not properly registered with the sheet edges. In addition, if the operator inadvertently installs a new supply roll in the wrong end to end relation, the copy paper is, in effect, up side down in relation to the various processing station through which the individual sheets pass, and photocopies cannot be successfully produced. That is, if the copy sheets are fed through the imaging station such that the image to be copied is projected on its back side rather than its photoconductive coating side, it will be appreciated that the system cannot, under this circumstance, perform properly.

It is accordingly an object of the present invention to provide an electrophotographic copy paper supply roll which cooperates with a unique supply roll mounting assembly to insure that the operator cannot improperly install a supply of electrophotographic copy paper in the photocopier. In other words, the copy paper supply roll and its mounting assembly are uniquely structured in accordance with'the present invention such as to be operator proof.

An additional object of the present invention is to provide an electrophotographic copy paper supply roll mounting assembly which is operative to automatically correct mis-alignments of the drawn off portion of the copy paper web relative to the supply roll and the copy paper feedpath throughthe photocopier.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

SUMMARY OF THE INVENTION In accordance with the present invention, there is provided a mounting assembly for an electrophotographic copy paper supply roll from which a web of copy paper is withdrawn for use in electrophotographic process, wherein the mounting assembly includes a spindle which is mounted against rotation by a pair of end brackets. The ends of the spindle are differently shaped and dimensioned, as are the spindle end receiving portions of the mounting brackets, such that the spindle can be successfully mounted by the end brackets only in a particular end to end relation. The spindle, in turn, mounts against rotation a pair of hubs of different diameters.

The supply roll of electrophotographic copy paper is provided with a core about which the copy paper is reverse or B wrapped, in that the photoconductive coating side of the copy paper faces outward. The core is formed having a stepped central bore such as to provide different bore diameters at each end which conform to the different diameters of the hubs.

To mount the supply roll on the assembly the spindle is removed from its end mounting brackets. One of the hubs is removed from the spindle in order to accommodate the insertion of the spindle through the central bore of the supply roll core. Suitable abutments or stops are carried by the spindle so as to insure that only one of the hubs can be removed therefrom. Due to the different diameters of the hubs and of the mating ends of the central bore in the core, the operator is compelled to insert the free end of the spindle through the central bore in the proper direction in order to successfully mount the supply roll for rotation on the hubs. The end brackets and the ends of the spindle are distinctively keyed such that the operator is forced to install the mounting assembly in the photocopier only in the proper end to end relation. As a consequence, installation of a new supply roll is effectively operator proof.

To accommodate supply rolls of different widths, the hubs are adjustably axially positioned on the spindle to permit the axial centering of supply rolls of varying widths on the mounting assembly.

The web of copy paper is withdrawn from the supply roll by an initial feed roller pair located in the copy paper feedpath of the system. Since the ends of the copy paper supply roll are frictionally mounted for rotation on the hubs, improper alignment or skewing of the leading end portion of the copy paper web extending from the supply roll to the initial feed roller pair is automatically corrected by virtue of the present invention. This is achieved by virtue of the fact that as long as the drawn off portion of the copy paper web is skewed, there is a differential drag exerted on the lateral edges of the drawn off portion which causes differential slippage along the nip of the initial feed roller pair in the feeding of the copy paper effective to progressively shift the drawn off portion into proper alignment.

The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts which will be exemplified in-the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

FIG. 1 is a longitudinal sectional view of an electrophotographic system employing the electrophotographic paper supply roll and mounting assembly therefor, as constructed in accordance with a preferred embodiment of the present invention;

FIG. 2 is a sectional view of the copy paper supply roll and mounting assembly, as taken along line 22 of FIG. 1;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2; 7

FIG. 4 is a sectional view takenalong line 4-4 of FIG. 2;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 2; and

FIG. 6 is a sectional view taken along line 66 of FIG. 1, wherein a supply roll of less than maximum width is accommodated on the mounting assembly.

Like reference numerals refer to corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION Referring first to FIG. 1, the electrophotographic copy paper supply roll, generally indicated at 10, and the mounting assembly therefor, generally indicated at 12, of the present invention are illustrated as being incorporated in an electro-photographic system such as disclosed and claimed in the copending, commonly assigned application of Lionel B. Hoffman and Isaac W. Sanders, entitled Electrostatic Photocopier Designed for Customer Serviceability, Ser. No. 131,064, filed Apr. 5, 1971. As will be appreciated from the description to follow, the apparatus of the present invention is not necessarily limited to any specific roll paper elec trostatic photocopier design and, indeed, may be used to advantage in other photocopier designs of this general type. As will be seen more clearly from the description of FIGS. 2 through 6 to follow, the supply roll 10 includes a core 14 on which is wrapped a web of electrophotographic copy paper 16. As is well understood in the art, electrophotographic copy paper generally consists of a photoconductive coating applied to one side of an electrically conductive paper substrate. The photoconductive coating typically consists of zinc oxide in a resin binder system.

The mounting assembly 12 includes, as will be more clearly seen in FIG. 2, a spindle 18 which is mounted against rotation to opposed side frame members 20 of the photocopier. The drawn off portion 16a of the copy paper web 16 is withdrawn from the underside of the supply roll 10 over a lower idler roller 22 and a lower guide 24 by a pair of initial feed rollers, commonly indicated at 26. The drawn off portion 16a is directed by upper and lower guides 28 between an upper stationary knife 30 and a lower rotatable knife 32 of a knife assembly 33. Lower knife 32 rotates upwardly to sever the copy paper web 16 on the cutting edge of upper knife 30 into successive sheets.

As was fully described in the above noted copending application, a handle 34 is pivotally mounted on the stub shafts at ends of the upper feed roller of the initial feed roller pair 26 and is rotated upwardly to forceably separate the initial feed roller pair. This facilitates the insertion of the drawn off portion 16a of the paper web 16 therebetween to start the copy paper supply and the proper alignment of the drawn off portion I6a relative to the supply roll and the initial feed roller pair. The installation ofa new supply roll 10 on mounting assembly 12 and the starting of the drawn off portion 16a of the copy paper web 16 is further facilitated by the proximate location of these components to the top ofthe copier housing 35, which is entered through a hinged access door 36.

The drawn off portion 16a of the copy paper web 16 is advanced by the initial feed rollers 26, and its leading edge is directed by upper and lower guides 38 to the nip of a next feed roller pair 40. Beyond this feed roller pair, the copy paper passes between an upper corona charging unit 42 and a lower corona charging unit 44 of a charging station 45. As is conventional in the art, the corona charging units are energized to impose uniform electrostatic charges of opposite polarity on the coated front surface and the back surface of the copy paper web as it passes therebetween.

The copy web 16 is drawn from the charging station 45 by feed roller pair 46. Beyond this feed roller pair, the leading edge of the copy paper web is intercepted by a guide 48 which acts to divert the copy paper web downwardly onto a vacuum conveyor, generally indicated at 50. The vacuum conveyor transports the copy paper downwardly along an image plane located in an imaging station, generally indicated at 52. As the copy paper moves through the imaging station, the charged surface of its photoconductive coating is subjected to an optical image reflected from an original document positioned at an illuminating station 54. As is well understood in the art, a document at the illuminating station 54 is illuminated by lamps 56, and the resulting optical image is reflected downwardly to a mirror 58. The mirror directs the image horizontally to projection optics, schematically indicated at 60, which acts to project the image borne by the original document onto the charged photoconductive coating surface of the copy paper at the image station 52.

As was disclosed in the above-noted copending application, the copy paper was imaged to produce the requisite electrostatic latent image thereon while in transit through the imaging station 52 by flash illumination of the original document at the illuminating station 54. It should be understood that the apparatus of the present invention is readily adaptable to electrophotographic systems employing other types of document scanning techniques.

From the imaging station 52, the copy paper, which by this time has been segmented by operation of the knife assembly 33, is conveyed to a development station, generally indicated at 62. The development station includes a tank 64 which contains a liquid developer for visibly developing the electrostatic latent image created on the copy paper sheet at the imaging station 52. The copy paper passes through a trough 66 and under an intensifier electrode 68 where it is submerged in the developer liquid. The copy paper sheet, now visibly developed with toner particles, is withdrawn from the development station 62 by a feed roller pair 70 and deposited on a conveyor 72 for conveyance through a drying station, generally indicated at 74. While in transit through the drying station, the successive copy paper sheets are subjected to drying air from a fan 76. A receiving compartment 78, stationed beyond the exit end of conveyor 72, accumulates successive copy sheets, indicated at 80, for ultimate removal by the operator.

The foregoing description of the copy paper feedpath is presented to illustrate one feature of the present invention; namely, the reverse or 8" wrapping of the copy paper web 16 on core 14 of the supply roll 10 such that the photoconductive coating thereon faces outwardly. By virtue of this reverse wrapping, the drawn off portion 16a of the copy paper web must be withdrawn from the underside of the supply roll 10 in order that the coated side face the projection optics while the copy paper is in the imaging station 52. It will be noted from FIG. 1 that, by virtue of this arrangement, the leading edge of the copy paper web 16 has a tendency, acquired from its storage on the supply roll 10, to curl toward the outboard side of its feedpath. This has the advantage that, in the event of a paper jam, there is a greater chance that the copy paper will accumulate on the outboard side of the copy paper feedpath and thus be more readily accessible for clearing by the operator. Moreover, thefact that the leading edge of the copy paper web has a tendency to curl in a direction opposite to the bends in its U-shaped feedpath insures that it will be picked up by the vacuum conveyor 50 as it is diverted from the upper horizontal segment to the vertical segment of the feedpath. Similarly, as the leading edge of the copy paper sheet leaves the imaging station and is diverted into the lower horizontal segment of the feedpath, the outward curl insures that the sheet will pass under the intensifier electrode 68 at the development station 62. Thus, the chances of a paper jam in the copy paper feedpath are significantly reduced by virtue of reverse or B wrapping of the copy paper web 16 on the supply roll and feeding the copy paper along a feedpath having bends or turns in the oppposite direction to the natural -curl of the copy paper.

Referring now to FIG. 2, spindle 18 of the supply roll I mounting assembly 12 is supported by a pair of end brackets 100 and 102 mounted by the copier side frame members 20. As seen in FIG. 3, bracket 100 is fixedly secured to its side frame 20 by screws 101, while bracket 102, as seen in FIGS. 2 and 4, is resiliently secured to its side frame 20 by a leaf spring 104. The upper bifurcated ends of this leaf spring are secured to the side frame by screws 105, while its lower end is suitably secured to end bracket 102 so as to urge spindle 18 to the left, as seen in FIG. 2. This references the left end of the spindle against left side frame member 20. Bracket 100 is formed with an upwardly opening recess 100a, while end bracket 102 is formed with an upwardly opening recess 102a, such that the ends of the spindle l8 are cradled by the end brackets. By virtue of the spindle mounting arrangement, it is seen that, to dismount the spindle, it is merely lifted upwardly to free the spindle ends from the end brackets.

As seen in FIGS. 3 and 4, end 18a of spindle l8 supported by bracket 100 is hex-shaped, while end 18b supported by bracket 102 is round. The bottom of recesses 100a and 102a are shaped to conform to the cross-sections of spindle ends 18a and 18b. The lateral dimension at the bottom of recess 102a is made smaller than the smallest diametrical dimension of spindle end 18a such that the spindle can only be mounted by the brackets in one end to end relationship; namely with spindle end 18a mounted by bracket 100 and spindle end 18b mounted by bracket 102. Thus the spindle ends and the brackets are keyed such that spindle 18 can only be mounted in one way. It will also be noted that by virtue of the hex cross-section of spindle end 118a supported by the fixed bracket 100, spindle 18 is mounted against rotation.

It will be appreciated that other spindle end and bracket recess configurations and dimensions may be utilized to removably mount the spindle against rotation and also to insure that the spindle can only be mounted in a specific end to end relationship, so as to be operator-proof."

Returning to FIG. 2, intermediate its ends, spindle 18 mounts a pair of hubs and 112, which in turn mount core 14 of supply roll 10. Each of the hubs has a central sleeve 114 accommodating a central aperture 116 through which spindle 18 is inserted. In the illustrated embodiment of the invention, the body of the spindle is hex-shaped, as is the central apertures 116 in hub sleeves 114. As a consequence, hubs 1 10 and 112 are mounted on spindle 18 against rotation. It will be appreciated that other provisions may be made for mounting the hubs on spindle 18 such as to inhibit their rotation thereon.

Core 14 of supply roll 10 is formed having a stepped bore so as to provide different bore diameters at each end of the core. Specifically, as seen in FIG. 2, central bore 14a in core 14 is provided with a raised section 14b which may be integrally formed with core 14 or constituted by an insert incorporated in the left end of the bore and secured to the core. The diameter of hub 110 is dimensioned so as to fit reasonably snugly into the central bore of core 14 and frictionally engaged raised section 1412. The diameter of hub 112 at the other end of the core is formed having a larger diameter so that this hub is snugly received therein to frictionally engage the other end of core 14-. Each of the hubs is provided with a flange 120 which bear against the ends of core 14 to determine the proper degree of insertion of the hubs into the central bore of the core.

From the description thusfar, it is seen that as the copy paper web 16 is withdrawn from the supply roll 10 by initial feed roller pair 26, neither the spindle 18 nor the hubs 110 and 112 rotate. Rather, core 14 of the copy paper supply roll rotates on the hubs. There is thus-provided a frictional drag on the withdrawal of copy paper which maintains the drawn off portion 16a of the copy paper web 16 extending from the supply roll to the initial feed rollers 26 taut at all times.

An additional benefit to this arrangement is that the mounting assembly of the present invention is automatically operative to correct any lateral mis-alignment of the leading end portion of the copy paper web 16 relative to the supply roll centrally mounted on mounting assembly 12. Typically, lateral edge guide marks are applied to a suitable stationary member, such as lower guide 24 (FIG. 1), to aid the operator in starting the copy paper web to align the leading end portion 16a such that its lateral edges are perpendicular to the spindle axes, i.e., aligned with the ends of the supply roll 10. If this is not done, the copy paper web and the sheets severed therefrom will be skewed as they are conveyed along the copy paper feedpath. However, if the leading end portion is skewed, the non-rotating hub in the end of the supply roll opposite to the direction of skew exerts a drag on that lateral edge of the web. There is essentially no drag on the other lateral edge of the web, which, being on the side of the direction of skew, is virtually slack. As the copy paper web 16 is withdrawn from the supply roll, this drag differential causes differential slippage across the width of the copy paper web as it is pulled by the initial feed roller pair such as to progressively shift the leading end portion 16a into alignment with the supply roll 10.

To accommodate supply rolls of varying widths (as see in FIGS. 2 and 6) the hubs 110 and 112 are constructed so as to be axially shiftable on spindle 18. To this end, the spindle is provided with a series of annular grooves 124 appropriately axially spaced to accommodate the various supply roll widths contemplated. The sleeves 114 of hubs 110 and 112 are provided with opposed, axially extending slots 126. A detent spring 128 is formed with a pair of pigtails 128a which, as seen in FIGS. and 6, extend through slots 126 in the hub sleeves 114 to engage in one of the annular grooves 124 in spindle 18. To adjust the axial positions of the hubs, they are merely forced axially on the spindle in the appropriate direction. The pigtails 128a simply ride out of the grooves 124 to permit the hubs to slide freely on the spindle 18. When the hubs approach their desired axial positions, the pigtails 128a of the detent springs 128 spring into the annular grooves located thereat to releasably retain the hubs.

Again referring to FIGS. 2 and 6, spindle 18 is further provided with a pair of fixed stops 130 and 132. Stop 132 is located somewhat to the right of the rightmost position of hub 112. Stop 132 serves as a locating guide for positioning the hub 112 such that its detent spring engages the right-most groove 124 in the spindle 18. When the appropriate end of the supply roll is mounted on hub 112, hub 110 at the other end is closely located by the roll width at the position where its detent spring 128 will engage the left-most angular groove 124, thus to centrally position a supply roll of maximum width on the spindle. Similarly, stop 130 serves to roughly locate the left-most position of hub 112, and upon the mounting of the supply roll on the two hubs, automatically locates the other hub 110 so as to centrally locate a supply roll of minimum width on the mounting assembly 12.

The stops 130 and 132 also serve the purpose of permitting removal of only hub 110 from t he spindle 18 by the operator pursuant to mounting a new copy paper supply roll 10. Since the stops flank hub 112, it cannot be removed from the spindle and thus there is no possibility of the operator inadvertently exchanging the positions of the hubs on the spindle.

lntegrally formed with spindle 18 to the right of stop 132 is a guide flange 133 which provides an enlarged guiding surface to allow ease of positioning and insertion of spindle end 18b into bracket 102.

From the foregoing description, it is seen that when the operator desires to replace copy paper supply roll 10, he lifts the spindle upwardly to disengage its ends from brackets 100 and 102. Hub 110 is slipped off of the left end of the spindle and the exhausted copy paper supply roll is removed and a full supply roll substituted. Since hub 112 remains on the spindle, the operator is forced to insert the free end of the spindle through the bore 14a of the supply roll core 14 from the wide diameter end. This insures proper mounting of the supply roll on the mounting assembly 12. After the operator has mounted the wide diameter end of core 14 on hub 112, hub 110 is remounted on the spindle and fitted into the smaller diameter end of the core, the spindle ends are then remounted in the end brackets and 112, and this can only be done in the proper manner due to the keying of the ends of the spindle and the bracket recesses. Thus, by virtue of the present invention the operator cannot improperly install the mounting assembly in the photocopier, and thus reloading of the hotocopier is truely operatorroof.

It W1 I thus e seen hat the ob ects set fort above,

among those made apparent from the preceding description, are efficiently attained and, since changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A mounting assembly for mounting a supply roll of electrophotographic copy paper between the side frames of an electrophotographic copying machine comprising:

A. a pair of brackets supported in opposed spaced relationship by the side frames of the photocopy machine, each of said brackets being formed to define recesses therein which terminate with different distinctive configurations,

B. a spindle having a length adapted to fit between the side frames of the photocopy machine and having end portions of a configuration corresponding to the configuration of said recesses of said brackets whereby said spindle is receivable in said brackets in only one orientation,

C. a pair of hubs mounted on said spindle in axially spaced relationship, said hubs having a cylindrical portion of dissimilar diameter with respect to each other and a radial flange portion adjacent the axially outer edge of said cylindrical portions, and

D. a cylindrical core upon which the electrophotographic copy paper is adapted to be wound, said core having a stepped bore providing dissimilar bore diameters at each end of the core corresponding to the diameters of said cylindrical portions of said hubs so that said core is receivable on said hubs in only one orientation, whereby a roll of copy paper including said core can be received in the photocopy machine in only one orientation.

2. The mounting assembly as set forth in claim 1 wherein said hubs are axially slidably mounted on said spindle to accommodate copy paper rolls of different width, and means are provided to retain said hubs in selected positions on said spindle said means comprising recesses formed in said spindle as spaced locations therealong, and spring retaining means carried by said hubs for engagement with said recesses to releasably hold said hubs in said selected locations. 

1. A mounting assembly for mounting a supply roll of electrophotographic copy paper between the side frames of an electrophotographic copying machine comprising: A. a pair of brackets supported in opposed spaced relationship by the side frames of the photocopy machine, each of said brackets being formed to define recesses therein which terminate with different distinctive configurations, B. a spindle having a length adapted to fit between the side frames of the photocopy machine and having end portions of a configuration corresponding to the configuration of said recesses of said brackets whereby said spindle is receivable in said brackets in only one orientation, C. a pair of hubs mounted on said spindle in axially spaced relationship, said hubs having a cylindrical portion of dissimilar diameter with respect to each other and a radial flange portion adjacent the axially outer edge of said cylindrical portions, and D. a cylindrical core upon which the electrophotographic copy paper is adapted to be wound, said core having a stepped bore providing dissimilar bore diameters at each end of the core corresponding to the diameters of said cylindrical portions of said hubs so that said core is receivable on said hubs in only one orientation, whereby a roll of copy paper including said core can be received in the photocopy machine in only one orientation.
 2. The mounting assembly as set forth in claim 1 wherein said hubs are axially slidably mounted on said spindle to accommodate copy paper rolls of different width, and means are provided to retain said hubs in selected positions on said spindle said means comprising recesses formed in said spindle as spaced locations therealong, and spring retaining means carried by said hubs for engagement with said recesses to releasably hold said hubs in said selected locations. 